I have unlocked quite a few pitches in Absolute pitch and then my computer crashed. I was able to locate the program and the folder that appears to have some files from each game. Is it possible to retrieve the level I've reach after reinstalling the game?

The ETC program doesn't need to be "installed". Once run, ETC does create a passel of data files (named ETC*). If those data files exist already, ETC reads the files and does not create new ones. So if you were to recover the ETC files (they are in the "User" folder in Windows and "Library" on a Mac) then you would be able to pick up exactly where you left off.